关于经典测量理论和项目反应理论中难度和区分度的探讨

The Discussion on Difficulty and Discrimination in Classical Test Theory and Item Response Theory

难度和区分度是心理测量或测验中的重要概念,它们在CTT和IRT框架中分别具有不同的特征。本研究在两种理论框架下,探讨难度和区分度的意义,指出基于IRT模型中的参数概念,可以更好地解释CTT中的难度和区分度的意义,两种理论中的难度值具有内在的函数关系。

Difficulty and discrimination are the important concepts in psychometrics and testing. There are different characteristics in CTT and IRT. This paper explores the meaning of difficulty and discrimination under the framework of two theories. The true meaning of difficulty and discrimination in crI~ can be well understood basing on the parameters＇ concept in IRT. In fact, the Function can be founded between difficulty in IRT and CTY.